Depending on the type and size of contactors being using, not only do
they generate a large inrush of current (most spec inrush current
as well as holding current), they can generate large amounts of EMI.

I found that I had to remove the controller assembly from the motor
starter cabinet to completly solve the problem (prior to redesigning it
to use a PIC).  I have yet to put it back in the same box, as it works
out cheaper to use seperate cabinets. These are 460 VAC 3 phase motor
controls.

hcooper@es.com